The purpose of this study is to determine the level of physical activity that can favorably reduce risk factors for congestive heart disease in Mexican American women. The specific aim is to determine the dose response of two levels of walking on cardiovascular outcomes in sedentary, obese women. Two experimental groups and one control group will be studied: one group will walk a distance of 2.4 km at 2.4 km/hr 5 days per week; the second group will walk a distance of 2.4 km 3 days per week at 4.8 km per hour. Baseline, 12 week, 24 week anthropometric measures, heart rate, blood pressure, height, weight and blood lipids will be measured.